Production of dispersions



-July 22, 1958 l.. T. WORK 2,844,541

PRODUCTION OF DISPERSIONS 4 f Filed sept. 9, 1955 ice n l 2,844,541PRODUCTION Vl? D lSPERSIONS Lincoln Thomas Work, Maplewood, N. J.,assignor to Texaco Development Corporation, NewYork, N. Y., n

va corporation of Delaware v vApplication September 9, 19,55, Serial No.533,328

13 claims. (cl. 252-314) v The present linvention relates to la novelmethod for producing dispersions of variousdi-spersoids in dispers-ingple.dispersions can be formed ofsodium, sulfur, paran wax and asphalt invarious liquid dispersion media such as hydrocarbons, water and thelike.

l Manylmeth'odsf of producing colloidal materials have previously beenused, such as, for example, the production of colloidal metals by meansof'an electric discharge,

the precipitation of colloidal material by'drowning a solu-y tion-in aynon-solvent, the Yprecipitation of linely divided substancesby' chemicalaction and the reduction of particle sizebyrnechanicalgrinding either inthe presence or absence of other solid or liquid material.

The product-ion of emulsions of oils or low melting media. TheV methodis applicable-to the production of l n emulsions offone liquid inanother, and of suspensions Vof a solid material in a liquid or semiliquid. For examwaxes in j water may be accomplished by mechanical v cmeans,..such as, for example, shaking or agitating a mechanicalst-irrer,but-in general, the method has been .limited to those..materials.whichare liquid, or which can easily be brought into a liquid condition.Furthermore, the various mechanical means for the production ofemulsions and suspensions are'generally attended by certaindisadvantages, such as, for example, operation on a batch yscale ratherthan continuously and the necessity forfthe usjejof power for operatingthe mechanical agitatv ing means, which adds to the cost of operation.In many cases, moreover, rapid agitation 'by mechanical methods 1 givesrise to'excessi-ve foaming.

My improved method for producing a dispersionof'a lfirst `substance ina'liquid dispersion medium comprises simultaneously passing the firstsubstance and the liquid together in astream through a heating zone,which may comprise along'tubular pipe arranged within a furnace.lv

The mixture is heated sufficiently to vap-orize part or all of theliquid dispersion medium to form vapor while maintaining the lirstsubstance unvaporized. The temperature shouldbesutlicientto melt the rstsubstance if it isv asolidV or semi'solid.v Then themixture and vaporare subjected to highvelocity and turbulent flow to break.

substance to liquid particles of extremely ne up I,the iirst size.- v vDispersion of the fine liquid particles in the dispersion mediumisexpedited by employing onlyy partial vaporization'of -the dispersionmedium, because the fine liquid particles produced during the operationconstantly enter into the unvaporized dispersion medium and aredispersed therein. l

When the rst substance is one which reacts readily with some atmospheresit is essential to exclude them during vthe operation. For example bothair and water l vapor must `bevexcluded fromcontact with sodium.

The eilluent of mixture and vapor is then cooled to condense .the vaporand solidify yany melted particles, thereby forming a dispersion ofextremely ne particles of the tirst substance in the liquid dispersionmedium. Ooolingmay be accomplished-by circulating a cooling 2 iluid inindirect heat exchange relationshipwith the efuent, or by injecting coolliquid, such as ladditional dispers-ion medium, directly into theeffluent for dilution and cooling thereof.

The method described is operable over a wide range of 4 proportions ofdispersion medium and dispersoid. For example, the amount of dispersoidcan range from as little as 5% of the mixture by weight to as ymuch as65%. The heat-ing zone may be within a pipe having dimensions based uponthe desired capacity of aplant. Di-

ameters may range from '1/2 to 2 inches for example, and lengths may beas little as and as much more or less. K

The invention is generally applicable to the treatmentV and suspensionsof various mercury compounds or copper compounds'in oil, sulfur andsodium in oil, sulfur in, p

water, and many other combinations to be used as fungiand chemicalreactants.

cides, insecticides, preservatives, delustrants, pigments,

The dispersion maybe etiected in the presenceof aj v protectivematerial. In general, by the expression`proj tective material ismeant'any dispersingagent, wetting f agentor protective colloid. Asspecic examples of such compositions may be mentioned glyptalmresins,4,gum

tragacanth, alkali metal salts of the higher fattyacids, .i galliacidsand their derivatives, agar-agar, glue,`methyl ,y

cellulose, *sulte cellulose lyes, sodiuml cellulose phthalate, calciumsaccharate, sodium cellulose glycollate, gela-Y tin, derivatives ofcholesterine, phosphatides, gelloses, v natural and artificial waxes,such as wool waxes, alkylol amine salts, quaternary ammonium compounds,clay, sulfonated tallow, sulfonated oils, alkyl sulfuric esters, kandalkali metal caseinates.

The materials -to 'be dispersed and the dispersing me-A dium may beintroduced into the heating zone in any suitable manner, and theproportions of the different com- In carrying out the ponents may bevaried as desired. process of the invention, the materials to bedispersed and the dispersing medium are brought together in the desiredproportion either by roughly mixing `the material-s in a singlecontainer, or by llowing the materialslfrom separate containersv intoamixing tube or chamber.

The dispersionsystemrproduced may vary Widely incharacter*dependinglargely lupon `the materials employed.

Thus,r they may consist of one or more different kinds-*of` .i

solid particles in a liquid suspending medium, bothsolid particles andliquid parti-cles in'a liquid dispersionrnedium,`oronfe or moredifferent kinds of liquid particlesin a liquid dispersion medium. v Thedispersion medium may contain more than one component, as forexample,.solutions of glycerine and Water (preferably 15.-'20.% water)are very desirable dispersion media for sulfur.

'I'he invention will be described further in detail below with referenceto the drawings, wherein:A f

Figs. l and 2 are schematic `flow diagrams showingl two alternativearrangements of apparatus for carrying out the invention.

Referring toFig. 1, the invention will be Vexemplified l as applied tothe production of a dispersion of solid particles of sodium-metal 'in aflowable dispersion medium which is inert to sodium and has'a boilingpointabove 2,844,541 l Patented July 22, 17958 ,il

as 1000 feet,

themelting point ofsodium, including among others the following:

Petroleum jelly Cetane Sodiumpuried uap'hthaleneV Nujol Tetralin TolueneDodecene- Dimethoxy decane Deobase kerosene Fuel oil Heptane Mineral oilNo. 33 2 White oil Xylene The `principles of course, also apply toallalkali metals including sodium, lithium, potasiurn, cesium, rubidium,and alloys of one with ,the other.

A mass of sodium metal is melted in the tank 11 by circulating a` hothydrocarbon liquid in indirect heat exchange relationship therewith.Molten sodium is passed by a pump 13 to the interior of a` heater 15 andinto a long pipe coil 17. Simultaneously a liquid dispersion medium suchas kerosene from a tank 19 ispassed by a pump21 into conjunction withthe stream of molten sodium at the entrance to the coil 17. The keroseneshould be above the melting point of sodium, 208.1 F., to preventsolidiication. This can be assured by passing the kerosene through apipe located within the heater 15 before it meets the sodium.

Thetwo streams of liquid mix intimately together and flow through thecoil 17 while the latter is heated in any suitableway. Preferablyheating is accomplished by heat exchange with a hot liquid such as ahigh boiling eutectic mixture of diphenyl and diphenyl oxide sold underthe trademark Dowtherm by the Dow Chemical Company (boiling point 258C.), but heating also may be done by a gas or oil flame. The mixture isheated to a temperature high enough to vaporize all or a substantialportion of the kerosene while maintaining the sodium in a molten state.-Consequently, the velocity and turbulence inthe coil increaseconsiderably as liquid vaporizes, the velocity being at least 25 feetper second, preferably above 100 feet per second, and often severalthousand feet per second.

As a result of the high velocity and the agitation produced by theextremely turbulent ow developed in the pipe coil the liquid sodium isconverted to tiny molten droplets which impinge against one another andagainst. the Walls of the tube until they are reduced to an extremely neparticle size such as 10 microns or less and predominantly less thanmicrons, a substantial proportion even being ner than one micron.

The mixture of liquid and vapor then leaves the pipe coil 17 and entersa cooler 23 wherein the Vapor is `condensed, the sodium particles aresolidified, and a dispersion is formed of extremely ne solid particlesof sodium suspended in kerosene. Cooling may be accomplished by ashcooling as the result of the reduced pressure, by circulating coolhydrocarbon liquid indirectly, or by injecting it directly into theeffluent Ifrom the pipe coil 17. If desired, chamber 23 can be aclassifier such as a cyclone sep arator to collect the liquid phasewhile removing vapors therefrom.

The resulting product can be used for performing various chemicalreactions in a well known way, asfor rening hydrocarbons, preparingalcohol-free alkoxides, or for halide condensation reactions.

Referring to Fig. 2, there is shown a modied system wherein thesubstance to be dispersed and the dispersing medium are mixed togetherin a mixer 29 and then passed simultaneously by a pump 31 into a pipecoil 33 which is heated to vaporize at least part of the liquid and forma rapidly flowing turbulent stream. In this modification dispersion isassured by splitting the efuent from coil 33 and passing the resultingtwo streams into a pair of diametrically opposed injector nozzles 35 and37 which discharge high velocity jets against one another with greatforcewithin a chamber 39. As a result of impingement of the particlesagainst one another they are further disintegrated tothe extremely linesize desired inthe ultimate products.

The downstream side of the chamber 39 constitutes a cooler 41 whereinthe product is suddenly cooled by direct or indirect heat exchange witha fluid, after which the resulting dispersion is discharged either forstorage or for direct consumption in a chemical process.

Example I Using the apparatus shown in Fig. 1, a large pool of moltensodium is maintained at a temperature of 2509 F. in the tank 11, and apool of deobase kerosene at a temperature of F. in the tank 19. Toassist dispersion the kerosene contains.0.5% of linseedfoil as adispersing agent.

The sodium and kerosene are pumped at rates of 200 pounds per hour eachinto conjunction with one another at the entranceY of heater coil 17composedi of 1A inch iron pipe 200feet long, the pressure being 200pounds per square inch gauge-(p. s. i. g.).

Before meeting the sodium stream, the kerosene stream;

sodium particles will have a` particle size distribution,

about as follows:

Microns: Percent of particles Less than 1 41 Example II A dispersionofsulfur in a water solution containing 12% ammonium caseinate isprepared by melting sulfur in tank` 11 and passing the molten sulfurtogether with hot water solution from tank 19 in equal quantities atarate of 300 pounds per hour each and a pressure of 250 p. s. i..g. intoa pipe coil 17 as described above. The contents of the coil are heated`to a maximum temperature of 410 F. so that about halfV of the watersolution-is vaporized and the liquid sulfur is converted by theturbulence andv high velocity. into tiny droplets which continuallyreenter the water phase and are dispersed therein. Upon entering cooler23 at atmospheric pressure there is formed a stable suspension of sulfurparticles in water solution.

Example III Using the apparatus shown in Fig. 2 a slurry is made up intank 29 of 50% solid parain wax particles in a water solution containing12% of sodium caseinate as a dispersing agent. pounds per hour and apressure of 200 p. s. i. g. intoa 1A; inch heater coil 33 250 feet longwherein the slurry is heated to 400 F., the wax melting and beingconverted by moderate turbulence and velocity into droplets owing alongvwith steam and water in the coil. The

eliluent from coil 33 enters the two nozzles 35 and 37 havingl; inchorices, and two jets are discharged against one another at an angle of180 to cause further disintegration of the `parain droplets to a sizesmall enough tov form a colloidal dispersion in water. Upon passingthroughV cooler 41 the mixture is cooled by indirect heat exchangewithwater and a dispersion is formed of tiny solid parain. particles inthe water solutionof sodium casemate.

Obviously, manymodifcations and Variations of the This slurry is passedat a rate of 400 i invention, as hereinbefore set forth, may be madewithout departing from the spirit andscope thereof, and therefore onlysuch limitations shc'uld be imposed as are indicated inthe appendedclaims.

I claim: v 1. A method for producing a dispersion of a rst normallysolid substance in a liquid dispersion medium which z is a non solventtherefor comprising simultaneously passf ing said iirst substance andsaid liquid together in a Vstream through a heating zone; heating saidmixture suiciently to melt saidrst substance and to vaporize at least asubstantial part of said liquid to vapor, while maintaining said iirstsubstance in a liquid condition; subjecting said mixture and said vaporto high velocity of at least l25 feet per second and turbulent tlowsutcient to break up said first substance to liquid particles ofextremely line size; and cooling said mixture and vapor, resolidify theparticles of saidlirst substance, to condense said vapor and form adispersion'ot extremely fine particles of said first substance in saidliquid dispersing medium.

2. A Amethod in accordance with claim l wherein said mixture is heatedsutiiciently to vaporize only part of said mixture, and wherein at leastpart of said particles ofextremely fine size reenter the unvaporizedpart of said mixture and are distributed therein prior to said coolingstep.

3. A method in accordance with claim l wherein said first substance isalkali vmetal and said liquid dispersing `non-solvent for sulfur.

6. A method in accordance with claim l wherein s'aiti` cooling step' isperformed :by circulating a cooling lluid in 1 y indirect heat exchangerelationship with said mixture and vapor.

7. A method in accordance with claim l wherein said cooling step 4isperformed by introducing additional disfr v persing medium into saidmixture and vapor.

8. A method in accordance with claim 1 whereinsaidY heating zone is anelongated heated tubular zone, and wherein said mixture and said vaporare subjected to high l velocity and turbulent ow during passage thereofthrough said tubular zone.

9. A method in accordance with claim l wherein said mixture and vaporare at least partly subjected to high 'velocity and turbulent llow bydischarging ,atleast two jets thereof against one another at highvelocity.

`l0. A method in accordance with claim 1 wherein said mixture is lirstformed upstream of said heating zone and is then passed into saidheating zone. i

ll. A method in accordance with claim l wherein said mixture is formedby p-assing separate streams of said substance and said dispersingmedium into said heatingv zone.

l2. A method in accordance with claim ll, also com-Av prising meltingsaid substance, and passing said substance as a molten stream intoassociation with said dispersing medium.

13. A method in accordance with claim wherein said mixture is heatedsuticiently to vaporize substantially all of said liquid to vapor.

References Cited in the file of this patent UNITED STATES PATENTS2,021,143

Calcott et al. Nov. 19, 1935 UNITED STATES PATENT OFFICE CERTIFICATE 0FCGRRECTION PatentJ No. 2,844,541 p July 22 1958 Lincoln Thomas Work Itis hereby certified that error appears in the printed specification ofthe above numbered patent requiring correction and that the said LettersPatent should read as corrected below.

Column 5, lines 18 and 19, strike out "to condense said Vapor" andinsert the same after "vapor" and before the comma in line 1'7, same lcolumn,

.Attesting Oiflcer Commissioner of Patents Signed and sealed this 2ndday of December 1958,

SEAL ttest:

KARL H., .AXLINE ROBERT C. WATSON .Attesting Ocer UNITED STATES PATENTOFFICE CERTIFICATE 0F CORECTION Patent No., 2,844,541 July 22g 1958Lincoln lihomas Work It is hereby certified that error appears in theprinted specification of the' above numbered patent requiring correctionand that the said Letters Patent should read as corrected below.

Column 5 lines l8 and 19 y strike out "to condense said vapor" andinsert the same after nvapor" and before the somma in line l'7, semeColumn Signed and sealed this 2nd day of December 1958c SEAL ttest:

KARL .AXLINE ROBERT C. WATSON Commissioner of Patents

1. A METHOD FOR PRODUCING A DISPERSION OF A FIRST NORMALLY SOLIDSUBSTANCE IN A LIQUID DISPERSION MEDIUM WHICH IS A NON SOLVENT THEREFORCOMPRISING SIMULTANEOUSLY PASSING SAID FIRST SUBSTANCE AND SAID LIQUIDTOGETHER IN A STREAM THROUGH A HEATING ZONE; HEATING SAID MIXTURESUFFICIENTLY TO MELT SAID FIRST SUBSTANCE AND TO VAPORIZE AT LEAST ASUBSTANTIAL PART OF SAID LIQUID TO VAPOR, WHILE MAINTAINING SAID FIRSTSUBSTANCE IN A LIQUID CONDITION; SUBJECTING SAID MIXTURE AND SAID VAPORTO HIGH VELOCITY OF AT LEAST 25 FEET PER SECOND AND TURBULENT FLOWSUFFICIENT TO BREAK UP SAID FIRST SUBSTANCE TO LIQUID PARTICLES OFEXTREMELY FINE SIZE; AND COOLING SAID MIXTURE AND VAPOR, RESOLIDIFY THEPARTICLES OF SAID FIRST SUBSTANCE, TO CONDENSE SAID VAPOR AND FORM ADISPERSION OF EXTREMELY FINE PARTICLES OF SAID FIRST SUBSTANCE IN SAIDLIQUID DISPERSING MEDIUM.